The present invention relates generally to the field of fuel cells and more specifically to fuel cell systems that are integrated with a hydrometer.
When a fuel cell system is operated on a water-containing fuel, an optimum water-to-fuel ratio is desirable in order for the fuel cell system to operate at peak efficiency. If the fuel does not contain the proper ratio, then water is either added or removed from the fuel. Adding or removing too much water poses a serious risk to the integrity of the fuel cell system. For instance, the risk of coking exists if too little water is added. Moreover, the water-to-fuel ratio of a given fuel source is not homogenous, because the fuel may “stratify” by density while it is stored in a fuel vessel (e.g., alcohol rises to the top and water lowers to the bottom of the vessel). Interrupting the operation of the fuel cell system to perform remedial water addition/removal further decreases the efficiency of the fuel cell system.